I had something similar (for years) and I actually found zazen and mindfulness very helpful. I think diving into ego death when via substances in uncontrolled

I had something similar (for years) and I actually found zazen and mindfulness very helpful. I think diving into ego death when via substances in uncontrolled settings isn't a great idea, because you can get bogged down in delusion and paranoia. I found it helpful with zazen to realise that any judgement of whatever I was experiencing (whether good or bad / joy or fear / enlightenment or hell), was just as much a delusion in itself as much as anything else. I personally found this made it illogical to be scared by whatever is happening inside your head, because that fear is just line noise.